The motivation for upgrading our PRNG is the recent buildbot failures in
the ZTS' tests/functional/fault/decompress_fault test. The probability
of a failure in that test is 0.8^256, which is ~1.6e-25 out of 1, yet we
have observed multiple test failures in it. This suggests a problem with
our random number generation.
The xorshift128+ generator that we were using has been replaced by newer
generators that have "better statistical properties". After doing some
reading, it turns out that these generators have "low linear complexity
of the lowest bits", which could explain the ZTS test failures.
We do two things to try to fix this:
1. We upgrade from xorshift128+ to xoshiro256++ 1.0.
2. We tweak random_get_pseudo_bytes() to copy the higher order
bytes first.
It is hoped that this will fix the test failures in
tests/functional/fault/decompress_fault, although I have not done
simulations. I am skeptical that any simulations I do on a PRNG with a
period of 2^256 - 1 would be meaningful.
Since we have raised the minimum kernel version to 3.10 since this was
first implemented, we have the option of using the Linux kernel's
get_random_int(). However, I am not currently prepared to do performance
tests to ensure that this would not be a regression (for the time
being), so we opt for upgrading our PRNG to a newer one from Sebastiano
Vigna.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13983
Microzap on-disk format does not include a hash tree, expecting one to
be built in RAM during mzap_open(). The built tree is linked to DMU
user buffer, freed when original DMU buffer is dropped from cache. I've
found that workloads accessing many large directories and having active
eviction from DMU cache spend significant amount of time building and
then destroying the trees. I've also found that for each 64 byte mzap
element additional 64 byte tree element is allocated, that is a waste
of memory and CPU caches.
Improve memory efficiency of the hash tree by switching from AVL-tree
to B-tree. It allows to save 24 bytes per element just on pointers.
Save 32 bits on mze_hash by storing only upper 32 bits since lower 32
bits are always zero for microzaps. Save 16 bits on mze_chunkid, since
microzap can never have so many elements. Respectively with the 16 bits
there can be no more than 16 bits of collision differentiators. As
result, struct mzap_ent now drops from 48 (rounded to 64) to 8 bytes.
Tune B-trees for small data. Reduce BTREE_CORE_ELEMS from 128 to 126
to allow struct zfs_btree_core in case of 8 byte elements to pack into
2KB instead of 4KB. Aside of the microzaps it should also help 32bit
range trees. Allow custom B-tree leaf size to reduce memmove() time.
Split zap_name_alloc() into zap_name_alloc() and zap_name_init_str().
It allows to not waste time allocating/freeing memory when processing
multiple names in a loop during mzap_open().
Together on a pool with 10K directories of 1800 files each and DMU
cache limited to 128MB this reduces time of `find . -name zzz` by 41%
from 7.63s to 4.47s, and saves additional ~30% of CPU time on the DMU
cache reclamation.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#14039
a6ccb36b94 had been intended to include
this to silence Coverity reports, but this one was missed by mistake.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14043
Calling zfs_refcount_remove_many() after freeing memory means we pass a
reference to freed memory as the holder. This is not believed to be able
to cause a problem, but there is a bit of a tradition of fixing these
issues when they appear so that they do not obscure more serious issues
in static analyzer output, so we fix this one too.
Clang's static analyzer found this with the help of CodeChecker's CTU
analysis.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14043
Callers will check if it has been set to NULL before trying to access
it, but never initialize it themselves. Whenever "one block spans two
iovecs", `crypto_get_ptrs()` will return, without ever setting
`*out_data_2 = NULL`. The caller will then do a NULL check against the
uninitailized pointer and if it is not zero, pass it to `memcpy()`.
The only reason this has not caused horrible runtime issues is because
`memcpy()` should be told to copy zero bytes when this happens. That
said, this is technically undefined behavior, so we should correct it so
that future changes to the code cannot trigger it.
Clang's static analyzer found this with the help of CodeChecker's CTU
analysis.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14043
Both Coverity and Clang's static analyzer complain about reading an
uninitialized intval if the property is not passed as DATA_TYPE_UINT64
in the nvlist. This is impossible becuase spa_prop_validate() already
checked this, but they are unlikely to be the last static analyzers to
complain about this, so lets just refactor the code to suppress the
warnings.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14043
Currently, additional/extra copies are created for metadata in
addition to the redundancy provided by the pool(mirror/raidz/draid),
due to this 2 times more space is utilized per inode and this decreases
the total number of inodes that can be created in the filesystem. By
setting redundant_metadata to none, no additional copies of metadata
are created, hence can reduce the space consumed by the additional
metadata copies and increase the total number of inodes that can be
created in the filesystem. Additionally, this can improve file create
performance due to the reduced amount of metadata which needs
to be written.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Dipak Ghosh <dipak.ghosh@hpe.com>
Signed-off-by: Akash B <akash-b@hpe.com>
Closes#13680
This patch handles the race condition on simultaneous failure of
2 drives, which misses the vdev_rebuild_reset_wanted signal in
vdev_rebuild_thread. We retry to catch this inside the
vdev_rebuild_complete_sync function.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Dipak Ghosh <dipak.ghosh@hpe.com>
Reviewed-by: Akash B <akash-b@hpe.com>
Signed-off-by: Samuel Wycliffe J <samwyc@hpe.com>
Closes#14041Closes#14050
Adds support for idmapped mounts. Supported as of Linux 5.12 this
functionality allows user and group IDs to be remapped without changing
their state on disk. This can be useful for portable home directories
and a variety of container related use cases.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes#12923Closes#13671
If we encounter an EXDEV error when using the redacted snapshots
feature, the memory used by dspp.fromredactsnaps is leaked.
Clang's static analyzer caught this during an experiment in which I had
annotated various headers in an attempt to improve the results of static
analysis.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13973
The pointer is to a structure member, so it is never NULL.
Coverity complained about this.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14042
range is always deferenced before it reaches this check, such that the
kmem_zalloc() call is never executed.
There is also no need to set `range->eos_marker = B_TRUE` because it is
already set.
Coverity incorrectly complained about a potential NULL pointer
dereference because of this.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14042
It is never NULL because we return early if dsl_pool_hold() fails.
This caused Coverity to complain.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14042
This is a circularly linked list. mg->mg_next can never be NULL.
This caused 3 defect reports in Coverity.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14042
Clang's static analyzer complained that we could use after free here if
the inner loop ever iterated. That is a false positive, but upon
inspection, the userland abd_alloc_chunks() function never will put
multiple consecutive pages into a `struct scatterlist`, so there is no
need to loop. We delete the inner loop.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14042
If mechanism->cm_param is NULL, passing mechanism to
PROV_SHA2_GET_DIGEST_LEN() will dereference a NULL pointer.
Coverity reported this.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14044
Calling spa_open() will pass a NULL pointer to spa_open_common()'s
config parameter. Under the right circumstances, we will dereference the
config parameter without doing a NULL check.
Clang's static analyzer found this.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14044
Clang's static analyzer pointed out that whenever zap_lookup_by_dnode()
is called, we have the following stack where strlcpy() is passed a NULL
pointer for realname from zap_lookup_by_dnode():
strlcpy()
zap_lookup_impl()
zap_lookup_norm_by_dnode()
zap_lookup_by_dnode()
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14044
clang-tidy caught this.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14044
After Linux 6.1-rc1 came out, the build started failing to build a
couple of the files in the linux spl code due to the mutex_init
redefinition. Moving the sys/mutex.h include to a lower position within
these two files appears to fix the problem.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#14040
This patch inserts the `static` keyword to non-global variables,
which where found by the analysis tool smatch.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes#13970
Out of the 12 defects in lua that coverity reports, 5 of them involve
`lua_typename()` and out of the dozens of defects in ZFS that lua
reports, 3 of them involve `lua_typename()` due to the ZCP code. Given
all of the uses of `lua_typename()` in the ZCP code, I was surprised
that there were not more. It appears that only 2 were reported because
only 3 called `lua_type()`, which does a defective sanity check that
allows invalid types to be passed.
lua/lua@d4fb848be7 addressed this in
upstream lua 5.3. Unfortunately, we did not get that fix since we use
lua 5.2 and we do not have assertions enabled in lua, so the upstream
solution would not do anything.
While we could adopt the upstream solution and enable assertions, a
simpler solution is to fix the issue by making `lua_typename()` return
`internal_type_error` whenever it is called with an invalid type. This
avoids the array overflow and if we ever see it appear somewhere, we
will know there is a problem with the lua interpreter.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13947
These were categorized as the following:
* Dead assignment 23
* Dead increment 4
* Dead initialization 6
* Dead nested assignment 18
Most of these are harmless, but since actual issues can hide among them,
we correct them.
That said, there were a few return values that were being ignored that
appeared to merit some correction:
* `destroy_callback()` in `cmd/zfs/zfs_main.c` ignored the error from
`destroy_batched()`. We handle it by returning -1 if there is an
error.
* `zfs_do_upgrade()` in `cmd/zfs/zfs_main.c` ignored the error from
`zfs_for_each()`. We handle it by doing a binary OR of the error
value from the subsequent `zfs_for_each()` call to the existing
value. This is how errors are mostly handled inside `zfs_for_each()`.
The error value here is passed to exit from the zfs command, so doing
a binary or on it is better than what we did previously.
* `get_zap_prop()` in `module/zfs/zcp_get.c` ignored the error from
`dsl_prop_get_ds()` when the property is not of type string. We
return an error when it does. There is a small concern that the
`zfs_get_temporary_prop()` call would handle things, but in the case
that it does not, we would be pushing an uninitialized numval onto
the lua stack. It is expected that `dsl_prop_get_ds()` will succeed
anytime that `zfs_get_temporary_prop()` does, so that not giving it a
chance to fix things is not a problem.
* `draid_merge_impl()` in `tests/zfs-tests/cmd/draid.c` used
`nvlist_add_nvlist()` twice in ways in which errors are expected to
be impossible, so we switch to `fnvlist_add_nvlist()`.
A few notable ones did not merit use of the return value, so we
suppressed it with `(void)`:
* `write_free_diffs()` in `lib/libzfs/libzfs_diff.c` ignored the error
value from `describe_free()`. A look through the commit history
revealed that this was intentional.
* `arc_evict_hdr()` in `module/zfs/arc.c` did not need to use the
returned handle from `arc_hdr_realloc()` because it is already
referenced in lists.
* `spa_vdev_detach()` in `module/zfs/spa.c` has a comment explicitly
saying not to use the error from `vdev_label_init()` because whatever
causes the error could be the reason why a detach is being done.
Unfortunately, I am not presently able to analyze the kernel modules
with Clang's static analyzer, so I could have missed some cases of this.
In cases where reports were present in code that is duplicated between
Linux and FreeBSD, I made a conscious effort to fix the FreeBSD version
too.
After this commit is merged, regressions like dee8934 should become
extremely obvious with Clang's static analyzer since a regression would
appear in the results as the only instance of unused code. That assumes
that Coverity does not catch the issue first.
My local branch with fixes from all of my outstanding non-draft pull
requests shows 118 reports from Clang's static anlayzer after this
patch. That is down by 51 from 169.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Cedric Berger <cedric@precidata.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13986
Before this patch, in zfs_domount, if zfs_root or d_make_root fails, we
leave zfsvfs != NULL. This will lead to execution of the error handling
`if` statement at the `out` label, and hence to a call to
dmu_objset_disown and zfsvfs_free.
However, zfs_umount, which we call upon failure of zfs_root and
d_make_root already does dmu_objset_disown and zfsvfs_free.
I suppose this patch rather adds to the brittleness of this part of the
code base, but I don't want to invest more time in this right now.
To add a regression test, we'd need some kind of fault injection
facility for zfs_root or d_make_root, which doesn't exist right now.
And even then, I think that regression test would be too closely tied
to the implementation.
To repro the double-disown / double-free, do the following:
1. patch zfs_root to always return an error
2. mount a ZFS filesystem
Here's the stack trace you would see then:
VERIFY3(ds->ds_owner == tag) failed (0000000000000000 == ffff9142361e8000)
PANIC at dsl_dataset.c:1003:dsl_dataset_disown()
Showing stack for process 28332
CPU: 2 PID: 28332 Comm: zpool Tainted: G O 5.10.103-1.nutanix.el7.x86_64 #1
Call Trace:
dump_stack+0x74/0x92
spl_dumpstack+0x29/0x2b [spl]
spl_panic+0xd4/0xfc [spl]
dsl_dataset_disown+0xe9/0x150 [zfs]
dmu_objset_disown+0xd6/0x150 [zfs]
zfs_domount+0x17b/0x4b0 [zfs]
zpl_mount+0x174/0x220 [zfs]
legacy_get_tree+0x2b/0x50
vfs_get_tree+0x2a/0xc0
path_mount+0x2fa/0xa70
do_mount+0x7c/0xa0
__x64_sys_mount+0x8b/0xe0
do_syscall_64+0x38/0x50
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Co-authored-by: Christian Schwarz <christian.schwarz@nutanix.com>
Signed-off-by: Christian Schwarz <christian.schwarz@nutanix.com>
Closes#14025
Various module parameters such as `zfs_arc_max` were originally
`uint64_t` on OpenSolaris/Illumos, but were changed to `unsigned long`
for Linux compatibility because Linux's kernel default module parameter
implementation did not support 64-bit types on 32-bit platforms. This
caused problems when porting OpenZFS to Windows because its LLP64 memory
model made `unsigned long` a 32-bit type on 64-bit, which created the
undesireable situation that parameters that should accept 64-bit values
could not on 64-bit Windows.
Upon inspection, it turns out that the Linux kernel module parameter
interface is extensible, such that we are allowed to define our own
types. Rather than maintaining the original type change via hacks to to
continue shrinking module parameters on 32-bit Linux, we implement
support for 64-bit module parameters on Linux.
After doing a review of all 64-bit kernel parameters (found via the man
page and also proposed changes by Andrew Innes), the kernel module
parameters fell into a few groups:
Parameters that were originally 64-bit on Illumos:
* dbuf_cache_max_bytes
* dbuf_metadata_cache_max_bytes
* l2arc_feed_min_ms
* l2arc_feed_secs
* l2arc_headroom
* l2arc_headroom_boost
* l2arc_write_boost
* l2arc_write_max
* metaslab_aliquot
* metaslab_force_ganging
* zfetch_array_rd_sz
* zfs_arc_max
* zfs_arc_meta_limit
* zfs_arc_meta_min
* zfs_arc_min
* zfs_async_block_max_blocks
* zfs_condense_max_obsolete_bytes
* zfs_condense_min_mapping_bytes
* zfs_deadman_checktime_ms
* zfs_deadman_synctime_ms
* zfs_initialize_chunk_size
* zfs_initialize_value
* zfs_lua_max_instrlimit
* zfs_lua_max_memlimit
* zil_slog_bulk
Parameters that were originally 32-bit on Illumos:
* zfs_per_txg_dirty_frees_percent
Parameters that were originally `ssize_t` on Illumos:
* zfs_immediate_write_sz
Note that `ssize_t` is `int32_t` on 32-bit and `int64_t` on 64-bit. It
has been upgraded to 64-bit.
Parameters that were `long`/`unsigned long` because of Linux/FreeBSD
influence:
* l2arc_rebuild_blocks_min_l2size
* zfs_key_max_salt_uses
* zfs_max_log_walking
* zfs_max_logsm_summary_length
* zfs_metaslab_max_size_cache_sec
* zfs_min_metaslabs_to_flush
* zfs_multihost_interval
* zfs_unflushed_log_block_max
* zfs_unflushed_log_block_min
* zfs_unflushed_log_block_pct
* zfs_unflushed_max_mem_amt
* zfs_unflushed_max_mem_ppm
New parameters that do not exist in Illumos:
* l2arc_trim_ahead
* vdev_file_logical_ashift
* vdev_file_physical_ashift
* zfs_arc_dnode_limit
* zfs_arc_dnode_limit_percent
* zfs_arc_dnode_reduce_percent
* zfs_arc_meta_limit_percent
* zfs_arc_sys_free
* zfs_deadman_ziotime_ms
* zfs_delete_blocks
* zfs_history_output_max
* zfs_livelist_max_entries
* zfs_max_async_dedup_frees
* zfs_max_nvlist_src_size
* zfs_rebuild_max_segment
* zfs_rebuild_vdev_limit
* zfs_unflushed_log_txg_max
* zfs_vdev_max_auto_ashift
* zfs_vdev_min_auto_ashift
* zfs_vnops_read_chunk_size
* zvol_max_discard_blocks
Rather than clutter the lists with commentary, the module parameters
that need comments are repeated below.
A few parameters were defined in Linux/FreeBSD specific code, where the
use of ulong/long is not an issue for portability, so we leave them
alone:
* zfs_delete_blocks
* zfs_key_max_salt_uses
* zvol_max_discard_blocks
The documentation for a few parameters was found to be incorrect:
* zfs_deadman_checktime_ms - incorrectly documented as int
* zfs_delete_blocks - not documented as Linux only
* zfs_history_output_max - incorrectly documented as int
* zfs_vnops_read_chunk_size - incorrectly documented as long
* zvol_max_discard_blocks - incorrectly documented as ulong
The documentation for these has been fixed, alongside the changes to
document the switch to fixed width types.
In addition, several kernel module parameters were percentages or held
ashift values, so being 64-bit never made sense for them. They have been
downgraded to 32-bit:
* vdev_file_logical_ashift
* vdev_file_physical_ashift
* zfs_arc_dnode_limit_percent
* zfs_arc_dnode_reduce_percent
* zfs_arc_meta_limit_percent
* zfs_per_txg_dirty_frees_percent
* zfs_unflushed_log_block_pct
* zfs_vdev_max_auto_ashift
* zfs_vdev_min_auto_ashift
Of special note are `zfs_vdev_max_auto_ashift` and
`zfs_vdev_min_auto_ashift`, which were already defined as `uint64_t`,
and passed to the kernel as `ulong`. This is inherently buggy on big
endian 32-bit Linux, since the values would not be written to the
correct locations. 32-bit FreeBSD was unaffected because its sysctl code
correctly treated this as a `uint64_t`.
Lastly, a code comment suggests that `zfs_arc_sys_free` is
Linux-specific, but there is nothing to indicate to me that it is
Linux-specific. Nothing was done about that.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Original-patch-by: Andrew Innes <andrew.c12@gmail.com>
Original-patch-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13984Closes#14004
Coverity complains about possible bugs involving referencing NULL return
values and division by zero. The division by zero bugs require that a
block pointer be corrupt, either from in-memory corruption, or on-disk
corruption. The NULL return value complaints are only bugs if
assumptions that we make about the state of data structures are wrong.
Some seem impossible to be wrong and thus are false positives, while
others are hard to analyze.
Rather than dismiss these as false positives by assuming we know better,
we add defensive assertions to let us know when our assumptions are
wrong.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13972
- Add a zfs_exit() call in an error path, otherwise a lock is leaked.
- Remove the fid_gen > 1 check. That appears to be Linux-specific:
zfsctl_snapdir_fid() sets fid_gen to 0 or 1 depending on whether the
snapshot directory is mounted. On FreeBSD it fails, making snapshot
dirs inaccessible via NFS.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Andriy Gapon <avg@FreeBSD.org>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Fixes: 43dbf88178 ("FreeBSD: vfsops: use setgen for error case")
Closes#14001Closes#13974
= Problem
While examining a customer's system we noticed unreasonable space
usage from a few snapshots due to gang blocks. Under some further
analysis we discovered that the pool would create gang blocks because
all its disks had non-zero write error counts and they'd be skipped
for normal metaslab allocations due to the following if-clause in
`metaslab_alloc_dva()`:
```
/*
* Avoid writing single-copy data to a failing,
* non-redundant vdev, unless we've already tried all
* other vdevs.
*/
if ((vd->vdev_stat.vs_write_errors > 0 ||
vd->vdev_state < VDEV_STATE_HEALTHY) &&
d == 0 && !try_hard && vd->vdev_children == 0) {
metaslab_trace_add(zal, mg, NULL, psize, d,
TRACE_VDEV_ERROR, allocator);
goto next;
}
```
= Proposed Solution
Get rid of the predicate in the if-clause that checks the past
write errors of the selected vdev. We still try to allocate from
HEALTHY vdevs anyway by checking vdev_state so the past write
errors doesn't seem to help us (quite the opposite - it can cause
issues in long-lived pools like the one from our customer).
= Testing
I first created a pool with 3 vdevs:
```
$ zpool list -v volpool
NAME SIZE ALLOC FREE
volpool 22.5G 117M 22.4G
xvdb 7.99G 40.2M 7.46G
xvdc 7.99G 39.1M 7.46G
xvdd 7.99G 37.8M 7.46G
```
And used `zinject` like so with each one of them:
```
$ sudo zinject -d xvdb -e io -T write -f 0.1 volpool
```
And got the vdevs to the following state:
```
$ zpool status volpool
pool: volpool
state: ONLINE
status: One or more devices has experienced an unrecoverable error.
...<cropped>..
action: Determine if the device needs to be replaced, and clear the
...<cropped>..
config:
NAME STATE READ WRITE CKSUM
volpool ONLINE 0 0 0
xvdb ONLINE 0 1 0
xvdc ONLINE 0 1 0
xvdd ONLINE 0 4 0
```
I also double-checked their write error counters with sdb:
```
sdb> spa volpool | vdev | member vdev_stat.vs_write_errors
(uint64_t)0 # <---- this is the root vdev
(uint64_t)2
(uint64_t)1
(uint64_t)1
```
Then I checked that I the problem was reproduced in my VM as I the
gang count was growing in zdb as I was writting more data:
```
$ sudo zdb volpool | grep gang
ganged count: 1384
$ sudo zdb volpool | grep gang
ganged count: 1393
$ sudo zdb volpool | grep gang
ganged count: 1402
$ sudo zdb volpool | grep gang
ganged count: 1414
```
Then I updated my bits with this patch and the gang count stayed the
same.
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#14003
If no errors are encountered, we read an uninitialized error value.
Clang's static analyzer complained about this.
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14007
First the function `memset(&key, 0, ...)` but
any call to "goto error;" would call zio_crypt_key_destroy(key) which
calls `rw_destroy()`. The `rw_init()` is moved up to be right after the
memset. This way the rwlock can be released.
The ctx does allocate memory, but that is handled by the memset to 0
and icp skips NULL ptrs.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes#13976
The metaslab_check_free() function only needs to be called in the
GANG|DEDUP|etc case because zio_free_sync() will internally call
metaslab_check_free().
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Finix1979 <yancw@info2soft.com>
Closes#13977
If the `list_head()` returns NULL, we dereference it, right before we
check to see if it returned NULL.
We have defined two different pointers that both point to the same
thing, which are `origin_head` and `origin_ds`. Almost everything uses
`origin_ds`, so we switch them to use `origin_ds`.
We also promote `origin_ds` to a const pointer so that the compiler
verifies that nothing modifies it.
Coverity complained about this.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13967
Some header files define structures like this one:
typedef const struct zio_checksum_info {
/* ... */
const char *ci_name;
} zio_abd_checksum_func_t;
So we can use `zio_abd_checksum_func_t` for const declarations now.
It's not needed that we use the `const` qualifier again like this:
`const zio_abd_checksum_func_t *varname;`
This patch solves the double const qualifiers, which were found by
smatch.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes#13961
Both Clang's Static Analyzer and Synopsys' Coverity would ignore
assertions. Following Clang's advice, we annotate our assertions:
https://clang-analyzer.llvm.org/annotations.html#custom_assertions
This makes both Clang's Static Analyzer and Coverity properly identify
assertions. This change reduced Clang's reported defects from 246 to
180. It also reduced the false positives reported by Coverityi by 10,
while enabling Coverity to find 9 more defects that previously were
false negatives.
A couple examples of this would be CID-1524417 and CID-1524423. After
submitting a build to coverity with the modified assertions, CID-1524417
disappeared while the report for CID-1524423 no longer claimed that the
assertion tripped.
Coincidentally, it turns out that it is possible to more accurately
annotate our headers than the Coverity modelling file permits in the
case of format strings. Since we can do that and this patch annotates
headers whenever `__coverity_panic__()` would have been used in the
model file, we drop all models that use `__coverity_panic__()` from the
model file.
Upon seeing the success in eliminating false positives involving
assertions, it occurred to me that we could also modify our headers to
eliminate coverity's false positives involving byte swaps. We now have
coverity specific byteswap macros, that do nothing, to disable
Coverity's false positives when we do byte swaps. This allowed us to
also drop the byteswap definitions from the model file.
Lastly, a model file update has been done beyond the mentioned
deletions:
* The definitions of `umem_alloc_aligned()`, `umem_alloc()` andi
`umem_zalloc()` were originally implemented in a way that was
intended to inform coverity that when KM_SLEEP has been passed these
functions, they do not return NULL. A small error in how this was
done was found, so we correct it.
* Definitions for umem_cache_alloc() and umem_cache_free() have been
added.
In practice, no false positives were avoided by making these changes,
but in the interest of correctness from future coverity builds, we make
them anyway.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13902
= Issue
Recently we hit an assertion panic in `dsl_process_sub_livelist` while
exporting the spa and interrupting `bpobj_iterate_nofree`. In that case
`bpobj_iterate_nofree` stops mid-way returning an EINTR without clearing
the intermediate AVL tree that keeps track of the livelist entries it
has encountered so far. At that point the code has a VERIFY for the
number of elements of the AVL expecting it to be zero (which is not the
case for EINTR).
= Fix
Cleanup any intermediate state before destroying the AVL when
encountering EINTR. Also added a comment documenting the scenario where
the EINTR comes up. There is no need to do anything else for the calles
of `dsl_process_sub_livelist` as they already handle the EINTR case.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#13939
2a493a4c71 was intended to fix all
instances of coverity reported unchecked return values, but
unfortunately, two were missed by mistake. This commit fixes the
unchecked return values that had been missed.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13945
ZED does not take any action for disk removal events if there is no
spare VDEV available. Added zpool_vdev_remove_wanted() in libzfs
and vdev_remove_wanted() in vdev.c to remove the VDEV through ZED
on removal event. This means that if you are running zed and
remove a disk, it will be properly marked as REMOVED.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#13797
The current value causes significant artificial slowdown during mass
parallel file removal, which can be observed both on FreeBSD and Linux
when running real workloads.
Sample results from Linux doing make -j 96 clean after an allyesconfig
modules build:
before: 4.14s user 6.79s system 48% cpu 22.631 total
after: 4.17s user 6.44s system 153% cpu 6.927 total
FreeBSD results in the ticket.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Closes#13932Closes#13938
Coverity caught unsafe use of `strcpy()` in `ztest_dmu_objset_own()`,
`nfs_init_tmpfile()` and `dump_snapshot()`. It also caught an unsafe use
of `strlcat()` in `nfs_init_tmpfile()`.
Inspired by this, I did an audit of every single usage of `strcpy()` and
`strcat()` in the code. If I could not prove that the usage was safe, I
changed the code to use either `strlcpy()` or `strlcat()`, depending on
which function was originally used. In some cases, `snprintf()` was used
to replace multiple uses of `strcat` because it was cleaner.
Whenever I changed a function, I preferred to use `sizeof(dst)` when the
compiler is able to provide the string size via that. When it could not
because the string was passed by a caller, I checked the entire call
tree of the function to find out how big the buffer was and hard coded
it. Hardcoding is less than ideal, but it is safe unless someone shrinks
the buffer sizes being passed.
Additionally, Coverity reported three more string related issues:
* It caught a case where we do an overlapping memory copy in a call to
`snprintf()`. We fix that via `kmem_strdup()` and `kmem_strfree()`.
* It caught `sizeof (buf)` being used instead of `buflen` in
`zdb_nicenum()`'s call to `zfs_nicenum()`, which is passed to
`snprintf()`. We change that to pass `buflen`.
* It caught a theoretical unterminated string passed to `strcmp()`.
This one is likely a false positive, but we have the information
needed to do this more safely, so we change this to silence the false
positive not just in coverity, but potentially other static analysis
tools too. We switch to `strncmp()`.
* There was a false positive in tests/zfs-tests/cmd/dir_rd_update.c. We
suppress it by switching to `snprintf()` since other static analysis
tools might complain about it too. Interestingly, there is a possible
real bug there too, since it assumes that the passed directory path
ends with '/'. We add a '/' to fix that potential bug.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13913
Coverity complains about a possible NULL pointer dereference. This is
impossible, but it suspects it because we do a NULL check against
`spa->spa_root_vdev`. This NULL check was never necessary and makes the
code harder to understand, so we drop it.
In particular, we dereference `spa->spa_root_vdev` when `new_state !=
POOL_STATE_UNINITIALIZED && !hardforce`. The first is only true when
spa_reset is called, which only occurs under fault injection. The
second is true unless `zpool export -F $POOLNAME` is used. Therefore,
we effectively *always* dereference the pointer. In the cases where we
do not, there is no reason to think it is unsafe. Therefore this change
is safe to make.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13905
Apply the fix from upstream.
http://www.lua.org/bugs.html#5.2.2-1https://www.opencve.io/cve/CVE-2014-5461
It should be noted that exploiting this requires the `SYS_CONFIG`
privilege, and anyone with that privilege likely has other opportunities
to do exploits, so it is unlikely that bad actors could exploit this
unless system administrators are executing untrusted ZFS Channel
Programs.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13949
In #13871, zfs_vdev_aggregation_limit_non_rotating and
zfs_vdev_aggregation_limit being signed was pointed out as a possible
reason not to eliminate an unnecessary MAX(unsigned, 0) since the
unsigned value was assigned from them.
There is no reason for these module parameters to be signed and upon
inspection, it was found that there are a number of other module
parameters that are signed, but should not be, so we make them unsigned.
Making them unsigned made it clear that some other variables in the code
should also be unsigned, so we also make those unsigned. This prevents
users from setting negative values that could potentially cause bad
behaviors. It also makes the code slightly easier to understand.
Mostly module parameters that deal with timeouts, limits, bitshifts and
percentages are made unsigned by this. Any that are boolean are left
signed, since whether booleans should be considered signed or unsigned
does not matter.
Making zfs_arc_lotsfree_percent unsigned caused a
`zfs_arc_lotsfree_percent >= 0` check to become redundant, so it was
removed. Removing the check was also necessary to prevent a compiler
error from -Werror=type-limits.
Several end of line comments had to be moved to their own lines because
replacing int with uint_t caused us to exceed the 80 character limit
enforced by cstyle.pl.
The following were kept signed because they are passed to
taskq_create(), which expects signed values and modifying the
OpenSolaris/Illumos DDI is out of scope of this patch:
* metaslab_load_pct
* zfs_sync_taskq_batch_pct
* zfs_zil_clean_taskq_nthr_pct
* zfs_zil_clean_taskq_minalloc
* zfs_zil_clean_taskq_maxalloc
* zfs_arc_prune_task_threads
Also, negative values in those parameters was found to be harmless.
The following were left signed because either negative values make
sense, or more analysis was needed to determine whether negative values
should be disallowed:
* zfs_metaslab_switch_threshold
* zfs_pd_bytes_max
* zfs_livelist_min_percent_shared
zfs_multihost_history was made static to be consistent with other
parameters.
A number of module parameters were marked as signed, but in reality
referenced unsigned variables. upgrade_errlog_limit is one of the
numerous examples. In the case of zfs_vdev_async_read_max_active, it was
already uint32_t, but zdb had an extern int declaration for it.
Interestingly, the documentation in zfs.4 was right for
upgrade_errlog_limit despite the module parameter being wrongly marked,
while the documentation for zfs_vdev_async_read_max_active (and friends)
was wrong. It was also wrong for zstd_abort_size, which was unsigned,
but was documented as signed.
Also, the documentation in zfs.4 incorrectly described the following
parameters as ulong when they were int:
* zfs_arc_meta_adjust_restarts
* zfs_override_estimate_recordsize
They are now uint_t as of this patch and thus the man page has been
updated to describe them as uint.
dbuf_state_index was left alone since it does nothing and perhaps should
be removed in another patch.
If any module parameters were missed, they were not found by `grep -r
'ZFS_MODULE_PARAM' | grep ', INT'`. I did find a few that grep missed,
but only because they were in files that had hits.
This patch intentionally did not attempt to address whether some of
these module parameters should be elevated to 64-bit parameters, because
the length of a long on 32-bit is 32-bit.
Lastly, it was pointed out during review that uint_t is a better match
for these variables than uint32_t because FreeBSD kernel parameter
definitions are designed for uint_t, whose bit width can change in
future memory models. As a result, we change the existing parameters
that are uint32_t to use uint_t.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13875
Coverity found a bug in `zfs_secpolicy_create_clone()` where it is
possible for us to pass an unterminated string when `zfs_get_parent()`
returns an error. Upon inspection, it is clear that using `strlcpy()`
would have avoided this issue.
Looking at the codebase, there are a number of other uses of `strncpy()`
that are unsafe and even when it is used safely, switching to
`strlcpy()` would make the code more readable. Therefore, we switch all
instances where we use `strncpy()` to use `strlcpy()`.
Unfortunately, we do not portably have access to `strlcpy()` in
tests/zfs-tests/cmd/zfs_diff-socket.c because it does not link to
libspl. Modifying the appropriate Makefile.am to try to link to it
resulted in an error from the naming choice used in the file. Trying to
disable the check on the file did not work on FreeBSD because Clang
ignores `#undef` when a definition is provided by `-Dstrncpy(...)=...`.
We workaround that by explictly including the C file from libspl into
the test. This makes things build correctly everywhere.
We add a deprecation warning to `config/Rules.am` and suppress it on the
remaining `strncpy()` usage. `strlcpy()` is not portably avaliable in
tests/zfs-tests/cmd/zfs_diff-socket.c, so we use `snprintf()` there as a
substitute.
This patch does not tackle the related problem of `strcpy()`, which is
even less safe. Thankfully, a quick inspection found that it is used far
more correctly than strncpy() was used. A quick inspection did not find
any problems with `strcpy()` usage outside of zhack, but it should be
said that I only checked around 90% of them.
Lastly, some of the fields in kstat_t varied in size by 1 depending on
whether they were in userspace or in the kernel. The origin of this
discrepancy appears to be 04a479f706 where
it was made for no apparent reason. It conflicts with the comment on
KSTAT_STRLEN, so we shrink the kernel field sizes to match the userspace
field sizes.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13876
When receiving full/newfs on existing dataset, then it should be done
with "-F" flag. Its enforced for initial receive in checks done in
zfs_receive_one function of libzfs. Similarly, on resuming full/newfs
recv on existing dataset, it should be done with "-F" flag.
When dataset doesn't exist, then full/new recv is done on newly created
dataset and it's marked INCONSISTENT. But when receiving on existing
dataset, recv is first done on %recv and its marked INCONSISTENT.
Existing dataset is not marked INCONSISTENT. Resume of full/newfs
receive with dataset not INCONSISTENT indicates that its resuming newfs
on existing dataset. So, enforce "-F" flag in this case.
Also return an error from dmu_recv_resume_begin_check() in zfs kernel,
when its resuming full/newfs recv without force.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Chunwei Chen <david.chen@nutanix.com>
Signed-off-by: Jitendra Patidar <jitendra.patidar@nutanix.com>
Closes#13856Closes#13857
Clang's static analyzer found a bad free caused by skein_mac_atomic().
It will allocate a context on the stack and then pass it to
skein_final(), which attempts to free it. Upon inspection,
skein_digest_atomic() also has the same problem.
These functions were created to match the OpenSolaris ICP API, so I was
curious how we avoided this in other providers and looked at the SHA2
code. It appears that SHA2 has a SHA2Final() helper function that is
called by the exported sha2_mac_final()/sha2_digest_final() as well as
the sha2_mac_atomic() and sha2_digest_atomic() functions. The real work
is done in SHA2Final() while some checks and the free are done in
sha2_mac_final()/sha2_digest_final().
We fix the use after free in the skein code by taking inspiration from
the SHA2 code. We introduce a skein_final_nofree() that does most of the
work, and make skein_final() into a function that calls it and then
frees the memory.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13954
Recently, I have been making a push to fix things that coverity found.
However, I was curious what Clang's static analyzer reported, so I ran
it and found things that coverity had missed.
* contrib/pam_zfs_key/pam_zfs_key.c: If prop_mountpoint is passed more
than once, we leak memory.
* module/zfs/zcp_get.c: We leak memory on temporary properties in
userspace.
* tests/zfs-tests/cmd/draid.c: On error from vdev_draid_rand(), we leak
memory if best_map had been allocated by a prior iteration.
* tests/zfs-tests/cmd/mkfile.c: Memory used by the loop is not freed
before program termination.
Arguably, these are all minor issues, but if we ignore them, then they
could obscure serious bugs, so we fix them.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13955
Coverity found a number of places where we either do MAX(unsigned, 0) or
do assertions that a unsigned variable is >= 0. These do nothing, so
let us drop them all.
It also found a spot where we do `if (unsigned >= 0 && ...)`. Let us
also drop the unsigned >= 0 check.
Reviewed-by: Neal Gompa <ngompa@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13871
Coverity complained about this. An error from `hkdf_sha512()` before uio
initialization will cause pointers to uninitialized memory to be passed
to `zio_crypt_destroy_uio()`. This is a regression that was introduced
by cf63739191. Interestingly, this never
affected FreeBSD, since the FreeBSD version never had that patch ported.
Since moving uio initialization to the top of this function would slow
down the qat_crypt() path, we only move the `memset()` calls to the top
of the function. This is sufficient to fix this problem.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13944
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.
Different approaches were used to handle the different cases of
unchecked return values:
* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
had no error handling. An error message was printed in another to
match the rest of the code.
* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
because the value is expected to be potentially unset.
* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
`(void)` because the values are expected to be potentially unset.
* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
wrong in ztest.
* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
because there is no guarantee that the zap entry will always be there.
For example, old pools imported readonly would not have it and we do
not want to fail here because of that.
* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
allocations sleep and thus can never fail.
* module/zfs/zvol.c: We dismiss the return value with `(void)` because
we do not need it. This matches what is already done in the analogous
`zfs_replay_write2()`.
* tests/zfs-tests/cmd/draid.c: We suppress one return value with
`(void)` since the code handles errors already. The other return value
is handled by switching to `fnvlist_lookup_uint8_array()`.
* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.
* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
ignore failures on remove() with (void) since it is expected to be
able to fail.
* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.
As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13920
Incorrectly sizing the array of hash locks used to protect the
dbuf hash table can lead to contention and reduce performance.
We could unconditionally allocate a larger array for the locks
but it's wasteful, particularly for a low-memory system.
Instead, dynamically allocate the array of locks and scale
it based on total system memory.
Additionally, add a new `dbuf_mutex_cache_shift` module option
which can be used to override the hash lock array size. This is
disabled by default (dbuf_mutex_hash_shift=0) and can only be
set at module load time. The minimum target array size is set
to 8192, this matches the current constant value.
Note that the count of the dbuf hash table and count of the
mutex array were added to the /proc/spl/kstat/zfs/dbufstats
kstat.
Finally, this change removes the _KERNEL conditional checks.
These were not required since for the user space build there
is no difference between the kmem and vmem interfaces.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13928
Richard Yao
Alexander Motin
Akash B
samwyc
youzhongyang
Coleman Kane
Tino Reichardt
Christian Schwarz
Mark Johnston
Serapheim Dimitropoulos
Jorgen Lundman
Finix1979
Ameer Hamza
Mateusz Guzik
Jitendra Patidar
Brian Behlendorf